Egypt deported a German citizen early Friday whom it detained in Cairo airport last month on suspicion of plotting terrorism, authorities said.

The 23-year-old Goettingen resident was repatriated on an early morning flight to Frankfurt in coordination with the German Embassy after being questioned by police, Cairo airport officials said. He had been detained on December 27.

Security officials say interrogations revealed the German of Egyptian origin believed in the extremist ideology of the Islamic State group. Egyptian authorities did not provide any evidence to support their allegations.